nfs: disintegrate UAPI for nfs

This is to complete part of the Userspace API (UAPI) disintegration for which
the preparatory patches were pulled recently.  After these patches, userspace
headers will be segregated into:

        include/uapi/linux/.../foo.h

for the userspace interface stuff, and:

        include/linux/.../foo.h

for the strictly kernel internal stuff.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 37 insertions, 14 deletions

diff --git a/net/core/scm.c b/net/core/scm.c
index 8f6ccfd..ab57084 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -45,12 +45,17 @@
 static __inline__ int scm_check_creds(struct ucred *creds)
 {
 	const struct cred *cred = current_cred();
+	kuid_t uid = make_kuid(cred->user_ns, creds->uid);
+	kgid_t gid = make_kgid(cred->user_ns, creds->gid);
+
+	if (!uid_valid(uid) || !gid_valid(gid))
+		return -EINVAL;
 
 	if ((creds->pid == task_tgid_vnr(current) || capable(CAP_SYS_ADMIN)) &&
-	    ((creds->uid == cred->uid   || creds->uid == cred->euid ||
-	      creds->uid == cred->suid) || capable(CAP_SETUID)) &&
-	    ((creds->gid == cred->gid   || creds->gid == cred->egid ||
-	      creds->gid == cred->sgid) || capable(CAP_SETGID))) {
+	    ((uid_eq(uid, cred->uid)   || uid_eq(uid, cred->euid) ||
+	      uid_eq(uid, cred->suid)) || capable(CAP_SETUID)) &&
+	    ((gid_eq(gid, cred->gid)   || gid_eq(gid, cred->egid) ||
+	      gid_eq(gid, cred->sgid)) || capable(CAP_SETGID))) {
 	       return 0;
 	}
 	return -EPERM;
@@ -149,39 +154,54 @@ int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *p)
 				goto error;
 			break;
 		case SCM_CREDENTIALS:
+		{
+			struct ucred creds;
+			kuid_t uid;
+			kgid_t gid;
 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct ucred)))
 				goto error;
-			memcpy(&p->creds, CMSG_DATA(cmsg), sizeof(struct ucred));
-			err = scm_check_creds(&p->creds);
+			memcpy(&creds, CMSG_DATA(cmsg), sizeof(struct ucred));
+			err = scm_check_creds(&creds);
 			if (err)
 				goto error;
 
-			if (!p->pid || pid_vnr(p->pid) != p->creds.pid) {
+			p->creds.pid = creds.pid;
+			if (!p->pid || pid_vnr(p->pid) != creds.pid) {
 				struct pid *pid;
 				err = -ESRCH;
-				pid = find_get_pid(p->creds.pid);
+				pid = find_get_pid(creds.pid);
 				if (!pid)
 					goto error;
 				put_pid(p->pid);
 				p->pid = pid;
 			}
 
+			err = -EINVAL;
+			uid = make_kuid(current_user_ns(), creds.uid);
+			gid = make_kgid(current_user_ns(), creds.gid);
+			if (!uid_valid(uid) || !gid_valid(gid))
+				goto error;
+
+			p->creds.uid = uid;
+			p->creds.gid = gid;
+
 			if (!p->cred ||
-			    (p->cred->euid != p->creds.uid) ||
-			    (p->cred->egid != p->creds.gid)) {
+			    !uid_eq(p->cred->euid, uid) ||
+			    !gid_eq(p->cred->egid, gid)) {
 				struct cred *cred;
 				err = -ENOMEM;
 				cred = prepare_creds();
 				if (!cred)
 					goto error;
 
-				cred->uid = cred->euid = p->creds.uid;
-				cred->gid = cred->egid = p->creds.gid;
+				cred->uid = cred->euid = uid;
+				cred->gid = cred->egid = gid;
 				if (p->cred)
 					put_cred(p->cred);
 				p->cred = cred;
 			}
 			break;
+		}
 		default:
 			goto error;
 		}
@@ -265,6 +285,7 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
 	for (i=0, cmfptr=(__force int __user *)CMSG_DATA(cm); i<fdmax;
 	     i++, cmfptr++)
 	{
+		struct socket *sock;
 		int new_fd;
 		err = security_file_receive(fp[i]);
 		if (err)
@@ -280,8 +301,10 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
 			break;
 		}
 		/* Bump the usage count and install the file. */
-		get_file(fp[i]);
-		fd_install(new_fd, fp[i]);
+		sock = sock_from_file(fp[i], &err);
+		if (sock)
+			sock_update_netprioidx(sock->sk, current);
+		fd_install(new_fd, get_file(fp[i]));
 	}
 
 	if (i > 0)